Many database systems can alter the data type of a column in a table. Altering the data type of a column can increase data compression in the database, and enable the database system to more efficiently analyze and manipulate column data. But altering the data type of a column is often compute intensive for the database system. Furthermore, the database system may need exclusive access to a table when altering the data type of a column. This causes the database to be unavailable to users for extended periods of time.
In the drawings, like reference numbers generally indicate identical or similar elements. Additionally, generally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.